<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>border</title>
    <style>
        .c1{
            width:400px;
            height: 200px;
            /* dotted是圆点,dashed是虚线 */
            /* border: 1px solid red; */
            /* border:5px solid red; */
            /* border:5px dotted red; */
            border:5px dashed red;
        }
        .c2{
            width:400px;
            height: 200px;
            /* border-width: 30px;  */
            /* 边框必须设置为solid才能看到边框图 有效果出来, 1*/
            border:30px solid transparent;
            /* border-image 的border,后面的27对应九宫格的4条裁剪线,也可以用百分比, 对应的是 top rignt bottome left, 如果都设置一样只写一个27就行了*/  /* round可以以整除的方式*/
            border-image:url(./border.png) 27 27 27 27 round ;
            
        }

        /* 利用边框实现梯形 */
        .c3{
            width:400px;
            height: 200px;
            border-bottom:30px solid red;
            /* border-right:30px solid blue; */
            border-left:30px solid transparent;
            border-right:30px solid transparent;
        }

        /*利用边框实现三角形  */
        .c4{
            width:0px;
            height: 50px;
            border-left:10px solid transparent;
            border-right:10px solid transparent;
            border-bottom:20px solid red;
        }
         /*利用边框实现扇形  */
        .c5{
            width:0px;
            height: 50px;
            border-left:10px solid transparent;
            border-right:10px solid transparent;
            border-bottom:20px solid blue;
            border-radius: 25px;

        }
    </style>
</head>
<body>
    <div class="c1">  </div>

    <div class="c2">  </div>

    <!-- 等腰梯形 -->
    <div class="c3">  </div>

    <!-- 三角形 -->
    <div class="c4">  </div>

    <!-- 扇形 -->
    <div class="c5">  </div>

</body>
</html>